PLATE LXI. 
STICTOPORA GRANTFERA. 
Page 257. 
Fig-. 1. A fragment of a frond, natural size, showing wide branches, much enlarged before bifurcation. 
Hamilton group. One mile north of Pavilion Village, Genesee county, N. Y. 
Fig. 2. An enlargement of a portion of another frond having narrower branches. 
Hamilton group. North Bristol township, Ontario county, N. Y. 
Fig. 3. An enlargement, showing the cell apertures obscured by the granulose striations. (X (5.) 
Fig. 4. An enlargement, showing the form and disposition of the cell apertures, which are unusually 
distinct in this specimen. (X ti.) 
Hamilton group. Fall-brook, four miles east of Canandaigua lake, N. Y. 
Fig. 5. An enlargement, showing the cell apertures with granulose peristomes, and intermediate striae. 
(X 18.) 
Hamilton group. York, Livingston county, N. Y. 
Fig. 6. An enlargement of transverse sections of two fronds. 
Ptilodictya parallela. 
Page 270. 
A fragment of a frond, natural size. 
An enlargement from the preceding, showing the form and arrangement of the cell apertures and 
the longitudinal striations. (X 8.) 
Hamilton group. Fall-brook, four miles east of Canandaigua lake, Ontario county, N. Y. 
Ptilodictya plumea. 
Page 271. 
A part of a. frond, natural size, showing- the manner of growth, and the frequent monticules of 
the surface. 
An enlargement from the portion of the frond immediately above fig. 11, showing oval cell aper¬ 
tures between the longitudinal striations. (X 18.) 
An enlargement of the base of the specimen fig. 9, showing the truncate apex, and striated 
portion above. (X 18.) 
An enlargement from the same frond, showing the form and disposition of the cell apertures, anil 
the elevated, granulose intermediate space. (X 6.) 
Hamilton group West Hamburg, Erie county, N- Y. 
Ptilodictya retiformis. 
Page 272. 
Fig. 13. An enlargement, showing the form and disposition of the cell apertures and the reticulate appear¬ 
ance of the surface. (X 6.) 
Hamilton group. Alden, Erie county, N. Y. 
Stictopora limata. 
Page 250. 
Fig. 14. A fragment, natural size. 
Fig. 15. An enlargement from the preceding, showing the small cell apertures and broad longitudinal 
ridges. (X 6.) 
Fig. 16. An enlargement of a narrower form, with less prominent longitudinal ridges. (X 6.) 
Hamilton group. Darien Centre, N. Y. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. i. 
Fig. 8. 
